The emerging and re-emerging human immunodeficiency virus epidemics in Europe

We provide a summary of the current status of the human immunodeficiency virus (HIV) epidemic, including data on the transmission of drug-resistant virus in the European Region of the WHO. The review was conducted by searching the reports of the European Centre for Disease Prevention and Control and the United Nations General Assembly Special Session country reports to identify the number of HIV cases reported in 2002-2011, the number of HIV tests performed, and the results of the most recent HIV surveys in at-risk groups. In the West, a 5-year linear trend analysis suggests an increase in the number of reported HIV cases in Belgium, Greece, and Iceland, and a decline in The Netherlands, Ireland, Portugal, Switzerland, and the UK. In the Centre, the number of reported cases increased in Bulgaria and Turkey, and in the East, the number of reported cases increased in Armenia, Georgia, and Ukraine. Estonia and Latvia reported a significant downward trend. HIV transmission in men who have sex with men (MSM) and heterosexual transmission accounted for, respectively, 40% and 38% of newly reported HIV cases in the West in 2011, whereas the epidemic in the Centre is predominantly concentrated in MSM. Although injection drug use remains the key driving force of the epidemic in the East, there is increasing evidence of sexual transmission from the core groups of injection drug users, and increasing spread within MSM. The pattern of transmitted drug resistance (TDR) is heterogeneous accross Europe; a significant number of clusters of TDR have been recently observed in several European countries.

Cellular HIV-1 DNA levels in drug sensitive strains are equivalent to those in drug resistant strains in newly-diagnosed patients in Europe

BACKGROUND

HIV-1 genotypic drug resistance is an important threat to the success of antiretroviral therapy and transmitted resistance has reached 9% prevalence in Europe. Studies have demonstrated that HIV-1 DNA load in peripheral blood mononuclear cells (PBMC) have a predictive value for disease progression, independently of CD4 counts and plasma viral load.

METHODOLOGY/PRINCIPAL FINDINGS

Molecular-beacon-based real-time PCR was used to measure HIV-1 second template switch (STS) DNA in PBMC in newly-diagnosed HIV-1 patients across Europe. These patients were representative for the HIV-1 epidemic in the participating countries and were carrying either drug-resistant or sensitive viral strains. The assay design was improved from a previous version to specifically detect M-group HIV-1 and human CCR5 alleles. The findings resulted in a median of 3.32 log(10) HIV-1 copies/10(6) PBMC and demonstrated for the first time no correlation between cellular HIV-1 DNA load and transmitted drug-resistance. A weak association between cellular HIV-1 DNA levels with plasma viral RNA load and CD4(+) T-cell counts was also reconfirmed. Co-receptor tropism for 91% of samples, whether or not they conferred resistance, was CCR5. A comparison of pol sequences derived from RNA and DNA, resulted in a high similarity between the two.

CONCLUSIONS/SIGNIFICANCE

An improved molecular-beacon-based real-time PCR assay is reported for the measurement of HIV-1 DNA in PBMC and has investigated the association between cellular HIV-1 DNA levels and transmitted resistance to antiretroviral therapy in newly-diagnosed patients from across Europe. The findings show no correlation between these two parameters, suggesting that transmitted resistance does not impact disease progression in HIV-1 infected individuals. The CCR5 co-receptor tropism predominance implies that both resistant and non-resistant strains behave similarly in early infection. Furthermore, a correlation found between RNA- and DNA-derived sequences in the pol region suggests that genotypic drug-resistance testing could be carried out on either template.

Chemokines CXCL10 and CXCL11 in the cerebrospinal fluid of patients with tick-borne encephalitis

OBJECTIVES

The aim of our study was to determine whether cerebrospinal fluid (CSF) of patients with tick-borne encephalitis (TBE) contains CXCL10, CXCL11, p40 subunit of interleukin-12 (IL-12)/IL-23, IL-18 and IL-15. We compared serum and CSF concentrations of CXCL10 and analysed the possible concentration gradient of this chemokine between the periphery and central nervous system.

MATERIALS AND METHODS

The study enrolled 19 TBE patients and 10 patients with non-inflammatory neurological diseases.

RESULTS

CSF of TBE patients contained CXCL10 (median 217 pg/ml), CXCL11 (8.3 pg/ml), p40 subunit of IL-12/IL-23 (38.9 pg/ml), IL-18 (30.1 pg/ml) and IL-15 (5.9 pg/ml). CXCL10 in the CSF of TBE patients was higher compared with serum (median 62 pg/ml, P < 0.001).

CONCLUSION

CSF of TBE patients contains CXCL10, CXCL11, p40 subunit of IL-12/IL-23, IL-18 and IL-15. Increased CXCL10 concentration in CSF suggests a role for this chemokine in the recruitment of CXCR3-expressing T-cells into the CSF of TBE patients.

Biological, epidemiological and clinical basis of understanding human immunodeficiency virus infection

Human immunodeficiency virus (HIV) causes a chronic infection beginning in most individuals with an acute syndrome followed by an asymptomatic stage and progresses in untreated adults over a median of 10 years to the late stage called AIDS. The virus rapidly and enormously replicates from the initiation of infection. The principal immunodeficiency caused by HIV is depletion in the subset of T lymphocytes referred to as helper T cells. New anti-HIV drugs given in potent combination regimens have demonstrated impressive efficacy by both clinical and laboratory measures, and have provided evidence that drugs can suppress HIV replication and disease manifestations. HIV/AIDS is still uncommon in Croatia. In the period from 1986 to 2000, 171 patients with AIDS have been reported of whom 101 (59%) died. The incidence of AIDS in 2000 was about 4 cases per million inhabitants. Recent testing of injection drug users at a needle exchange program (Help, Split) revealed an HIV incidence of about 1%.